孵化温度对中华鳖胚胎物质和能量利用的影响

用多重温度组合[7个恒温（23、24、27、28、30、33和34℃）和1个波动温度（22．3－32．8℃）]孵化中华鳖（Pellodiscus sinensis）卵,检测温度对胚胎利用卵内物质和能量的影响。卵在波动温度和温和温度下（27℃和28℃）孵化有较高的干物质、脂肪和能量转化率,卵出幼体因而含有较多的无机物,幼体躯干和脂肪体含有较高的能量。卵在极端高温（34℃和33℃）或极端低温（23℃）下孵化物质和能量转化率较低,使得孵出幼体中无机物较少,幼体射干和脂肪中含能量较低。孵化温度显著影响中华鳖孵出幼体内的能量分配;27℃和28℃孵出幼体含能量较高且相似,但27℃孵出幼体剩余卵黄能量小于28℃孵出幼体;34℃和23℃孵出幼体含能量较低且相似,但23℃孵出幼体剩余卵黄能量大于34℃孵出幼体。波动温度拓宽存活孵化温度范围。     

温度对台湾红罗非鱼能量收支的影响

于１９９６年７－８月在盐度为１４的条件下,测定了台湾红罗非鱼（体重２５．３３４－２６．２２５ｇ）在水温为２２、２８和３４℃时的能量收支,结果表明,温度对台湾红罗非鱼的特定生长率,转化效率和最大摄食率均有显著影响,２８℃时上述各值均达到最大,分别为１．７９,６０．０１％和２．５９％Ｂ．Ｗ．ｄ＾－１;对吸收率无显著影响,对于物质的吸收率的平均值为６４．５８％、温度对食物能分配于能量支出各部分的比例有显     

国产沙参属五个种的核型研究

首次报道了５种国产沙参属（Ａｄｅｎｏｐｈｏｒａ）植物的染色体数目和核型。北方沙参Ａ．ｂｏｒｅａｌｉｓＨｏｎｇｅｔＹ．Ｚ．Ｚｈａｏ的核型公式为２ｎ＝３４＝２８ｍ＋４ｓｍ（２ｓａｔ）＋２ｓｔ（２ｓａｔ）;雾灵沙参Ａ．ｗｕｌｉｎｇｓｈａｎｉｃａＨｏｎｇ的核型公式为２ｎ＝３４＝２６ｍ（４ｓａｔ）＋６ｓｍ＋２ｓｔ或２ｎ＝３４＋１Ｂ＝２６ｍ（４ｓａｔ）＋６ｓｍ＋２ｓｔ＋１Ｂ;秦岭沙参Ａ．ｐｅｔｉｏｌａｔａＰａｘｅｔＨｏｆｍ．的核型公式为２ｎ＝３４＝２６ｍ（２ｓａｔ）＋６ｓｍ＋２ｓｔ或２ｎ＝３４＋１Ｂ＝２６ｍ（２ｓａｔ）＋６ｓｍ＋２ｓｔ＋１Ｂ;裂叶沙参Ａ．ｌｏｂｏｐｈｙｌａＨｏｎｇ的核型公式为２ｎ＝３４＝２６ｍ＋４ｓｍ（２ｓａｔ）＋４ｓｔ或２ｎ＝３４＋２Ｂ＝２６ｍ＋４ｓｍ（２ｓａｔ）＋４ｓｔ＋２Ｂ。泡沙参Ａ．ｐｏｔａｎｉｎｉＫｏｒｓｈ的核型公式为２ｎ＝３４＝２８ｍ（２ｓａｔ）＋４ｓｍ＋２ｓｔ。它们同以往报道的其它种的核型相似：以中部着丝点染色体（ｍ）为主,至少具一对近端着丝点染色体（ｓｔ）和一对随体染色体,核型的对称程度较高,着丝点端化值（Ｔ．Ｃ）为５８．４％～６２．０％。结合其它性状,讨论了裂叶沙参的特殊性     

孵化温度对火赤链游蛇幼体特征的影响兼评剩余卵黄的功能

研究３ 个温度中孵出火赤链游蛇（ Ｄｉｎｏｄｏｎ ｒｕｆｏｚｏｎａｔｕｍ） 幼体的特征并评估剩余卵黄的功能。孵化温度显著影响孵化期和孵出幼体的体长和尾长。与其他类似研究结果不同的是, 低温（２４℃） 孵出的幼体体长和尾长小于较高温度（２８ ℃和３０ ℃） 孵出的幼体。在２４ ～３０℃温度范围内, 孵化温度对孵化成功率、胚胎对卵内物质和能量的利用、幼体的性比和畸形率、孵出幼体总干重及躯干长、剩余卵黄和脂肪体干重无显著影响。孵出的雄性幼体数量显著多于雌性幼体。剩余卵黄的主要功能是用于孵出幼体的早期维持和躯干的生长。新生卵内容物中８１－４ ％ 的干物质、７０－０％ 的脂肪和７９－４ ％ 的能量在孵化过程中被转移到幼体。     

四种无尾两栖动物的核型和银染

本文报道了二种角蟾和二种树蛙的核型和银染ＮＯＲ：无量出角蟾：２ｎ＝２６（２４＋２ＳＭ），５＋８，ＳＣ和Ａｇ－ＮＯＲｓ位于６ｑ＾ｐｅｒ沙坪角蟾：２ｎ＝２６（１６Ｍ＋８ＳＭ＋２ＳＴ），５＋８，ＳＣ位于１ｑ＾ｐｅｒ，但Ａｇ－ＮＯＲｓ有二对，分别是ｌｑ＾ｐｅｒ和２ｑ＾ｐｅｒ；黑蹼树蛙：２ｎ＝２６（２４Ｍ＋２ＳＭ），５＋８，ＳＣ和Ａｇ－ＮＯＲｓ在ｌｐ＾ｉｎｔｅｒ；背条跳树蛙；２ｎ＝１６（１２Ｍ＋４ＳＭ），Ｓ     

巴拉斯自鹤芋的组织培养和快速繁殖

１植物名称巴拉斯白鹤芋（Ｓｐａｔｈｉｐｈｙｌｌｕｍｐａｌａｓ）。２材料类别小苗茎尖或茎段。３培养条件以ＭＳ为基本培养基：（１）诱导分化与生长培养基为ＭＳ＋ＢＡ２ｍｐ·Ｌ－１（单位下同）＋ＮＡＡ０．２＋３％蔗糖;（２）生根培养基为１／２ＭＳ＋ＩＢＡ０．２＋１．５％蔗糖。以上培养基均加０．７５％琼脂,ｐＨ５．８,培养温度２６～２８℃,每日光照１０～１２ｈ,光照度１５００～２５００ｌｘ。４生长与分化情况剪取顶芽或茎段约０．５～１．０ｃｍ长,用７０％～７５％乙醇消毒３０～６０ｓ,以０．１％ＨｇＣｌ２溶液…     

光周期对中华鳖稚鳖摄食、生长和能量转换的影响

在水温２９±１℃,光照强度５００ｌｘ的条件下,研究了不同光周期对中华鳖稚鳖的最大日摄食量、最大日摄食率、特定生长率、同化效率、消化时间和生长效率的影响。结果表明,光周期对中华鳖稚鳖的上述各指标均无显著影响。随体重的增加,中华鳖稚鳖的最大日摄食量逐渐增大,而最大日摄食率则逐渐减少。在人工养殖中华鳖稚鳖过程中,光照周期的选择是次要的     

玫瑰海棠的组织培养及快速繁殖

１植物名称玫瑰海棠（Ｂｅｇｏｎｎｉａ　ｍａｎｎｉｉ）。２材料类别幼芽、叶片。３培养条件以ＭＳ为基本培养基。诱导丛生芽培养基：（１）ＭＳ＋ＫＴ１．０ｍｐ·Ｌ－１（单位下同）＋ＮＡＡ０．１。丛生芽增殖培养基：（２）ＭＳ＋ＫＴ１．０＋ＮＡＡ０．０５;（３）ＭＳ＋６－ＢＡ０．５＋ＮＡＡ０．０５。诱导生根培养基：（４）１／２ＭＳ＋ＮＡＡ０．２。上述培养基均加３％蔗糖,０．８％琼脂,ｐＨ５．８。培养温度（２６±２）℃,光照度约为２０００ｌｘ,光照１４ｈ·ｄ－１。４生长与分化情况４．１无菌材料的获得将玫瑰海棠…     

四种风毛菊属植物的核型研究

本文首次报道产于我国华北地区风毛菊属（ＳａｕｓｓｕｒｅａＤＣ．）４种植物的染色体数目和核型。四个种的染色体数目均是２ｎ＝２６,都是２倍体。它们的核型是：糠风毛菊（Ｓ．Ｐａｌｅａｔａ）Ｚｎ＝２ｘ＝２６＝１８ｍ＋６ｓｍ＋２ｓｔ,属２Ｂ型,华北风毛菊（Ｓ．ｍｏｎｇｏｌｉｃａ）Ｚｎ＝２ｘ＝２６＝１４ｍ＋４ｓｍ＋８ｓｔ,属２Ｂ型;狭苞凤毛菊（Ｓ．ｄｉｅｌｓｉａｎａ）Ｚｎ＝２ｘ＝２６＝８ｍ＋１２ｓｍ＋６ｓｔ,属２Ｃ型;银背凤毛菊（Ｓ．ｎｉｖｅａ）２ｎ＝２ｘ＝２６＝１８ｍ＋６ｓｍ＋２ｓｔ,属２Ａ型。染色体中均未发现随体。     

环境温度对(虫)蜓能量需求和食物同化影响的研究

研究了环境温度对成体Yan蜓能量需求和食物同化的影响。在24℃—33℃范围内,雌、雄Yan蜓摄入能、表观消化系数和同化效率的两性差异不显著。温度显著影响Yan蜓的能量摄入和同化效率,27℃时的能量摄入显著高于30℃和33℃,27℃时的同化效率显著高于24℃和33℃。各实验温级表观消化系数的差异不显著。结果表明：环境温度对Yan蜓能量需求和食物同化的影响显著。     

日光温室采光面三效率计算模式及其优化选择研究

本文针对日光温室常见的3种采光面（圆弧面、椭圆和抛物面）,给出了各自采光效率、土地使用率和保温效率（简称三效率）的理论计算模式,并通过分析得出,各个高效采光面上的采光效率均随纬度增加而降低,随距冬至的日数而增加,随作物高度而降低,随高跨比增加而增加。在三种采光面中,无论时间、地点、高跨比和种植高度怎样变化,均以圆弧面的采光效率为最高,椭圆面次之,抛物面最低。另一方面,从土地使用效率来看,椭圆面最高,但它的保温效率最低。因此,采光面形状的选择应因使用对象而宜,本文给出了最佳选择建议。     

Dimensionless criteria for estimating oxygen transfer in aeration systems

The effect of power consumption on oxygen transfer efficiency has been evaluated for both surface and subsurface aeration systems. Two new dimensionless criteria (numbers) have been proposed for this purpose. They are termed the efficiency criterion or T(o) number and the power consumption effect criterion or Av number. The analysis presented in this article is based on data obtained on various full-scale aeration systems, and it shows that for each aerator there is an optimum power consumption at which maximum oxygen transfer efficiency results. The oxygen transfer efficiency has maximum values when the efficiency criterion (T(o) number) reaches an approximately constant value. The results have proven that when there are several aerators with identical diameters and the same rotational velocity but different geometrical shapes, the most efficient one will be (after having reached the maximum transfer efficiency) the one with the highest power consumption. For two aerators varying in diameter but with the same parameter as above (maximum transfer, equal rotational velocity), different efficiencies are obtained, the difference being a function of d(-0.5). The results of investigating subsurface aeration systems show that the efficiency of decreased.     

Revised algorithm of ecosystem water use efficiency for semi-arid steppe in the Loess Plateau of China

Aims We evaluated the applicability of different measures of water use efficiency through analyzing the coupled dynamics of GPP and evapotranspiration in the semi-arid steppe in the Loess Plateau of China. Our objective is to explore the applicability of two quantitative measures of ecosystem water use efficiency—inherent water use efficiency (IWUE) and underlying water use efficiency (uWUE) —for the semi-arid steppe and to endeavor necessary modifications.Methods The consistency and stability of three indices of water use efficiency formulations (i.e. WUE, IWUE, uWUE) were calculated and compared at hourly, daily and annual time scales before proposing an optimal water use efficiency (oWUE). These indices were additionally used to quantify their importances in modeling the diel change of gross primary production (GPP). The yielded-accuracy of the prediction was used for justifying their uses.Important findings IWUE and uWUE appeared suitable for examining the coupled water-carbon characteristics of vegetation at hourly and daily scales, whereas WUE was more plausible on the annual and interannual scales. The optimized water use efficiency index did not improve the prediction of the coupled water-carbon characteristics as compared with uWUE, but it improved the prediction of GPP and its dynamics. oWUE and uWUE improved the predictions of GPP in the peak growing period, while WUE predicted the GPP better at the early and late growing season. Interestingly, we found that IWUE was not suitable for predicting GPP and its dynamics. The results will be of great importance in modeling the effects of climate change on the carbon assimilation and water cycle for the future.     

Nutritional properties of four marine microalgae for albino rats

The nutritive value of the marine microalgaeTetraselmis suecica, Isochrysis galbana, Dunaliella tertiolecta andChlorella stigmatophora was studied in diets given to rats. Biological assays were carried out in order to determine the Protein Efficiency Ratio (PER) and the Food Conversion Efficiency (FCE). Each dried microalga was fed to weaning Wistar albino rats as the sole protein source at a protein level of 12%. Control rats were given diets containing 12 % casein. Food consumption was similar in all groups. PER values obtained were 1.14 withT. suecica diet, 1.13 withI. galbana diet, 2.07 withD. tertiolecta diet and 1.13 withC. stigmatophora diet (casein, 2.50). FCE values followed a similar pattern. The data showed that the marine microalgaD. tertiolecta is a source of protein of good quality. Its PER is quite high, compared to vegetable and cereal proteins, and compares favourably with other microbial protein sources, such as yeasts or different freshwater microalgae. Haematological tests showed no significant differences among the groups in haemoglobin levels, red and white blood cell counts, differential count and mean corpuscular volume. Different blood parameters were also determined and a significant decrease in triglycerides levels appeared with all the microalgal diets, whereas a significant decrease in cholesterol appeared inD. tertiolecta andC. stigmatophora diets.     

Cycling efficiency and pedalling frequency in road cyclists

The purpose of this study was to determine the influence of pedalling rate on cycling efficiency in road cyclists. Seven competitive road cyclists participated in the study. Four separate experimental sessions were used to determine oxygen uptake (VO(2)) and carbon dioxide output (VCO(2)) at six exercise intensities that elicited a VO(2) equivalent to 54, 63, 73, 80, 87 and 93% of maximum VO(2) (VO(2max)). Exercise intensities were administered in random order, separated by rest periods of 3-5 min; four pedalling frequencies (60, 80, 100 and 120 rpm) were randomly tested per intensity. The oxygen cost of cycling was always lower when the exercise was performed at 60 rpm. At each exercise intensity, VO(2) showed a parabolic dependence on pedalling rate (r = 0.99-1, all P < 0.01) with a curvature that flattened as intensity increased. Likewise, the relationship between power output and gross efficiency (GE) was also best fitted to a parabola (r = 0.94-1, all P < 0.05). Regardless of pedalling rate, GE improved with increasing exercise intensity (P < 0.001). Conversely, GE worsened with pedalling rate (P < 0.001). Interestingly, the effect of pedalling cadence on GE decreased as a linear function of power output (r = 0.98, n = 6, P < 0.001). Similar delta efficiency (DE) values were obtained regardless of pedalling rate [21.5 (0.8), 22.3 (1.2), 22.6 (0.6) and 23.9 (1.0)%, for the 60, 80, 100 and 120 rpm, mean (SEM) respectively]. However, in contrast to GE, DE increased as a linear function of pedalling rate (r = 0.98, P < 0.05). The rate at which pulmonary ventilation increased was accentuated for the highest pedalling rate (P < 0.05), even after accounting for differences in exercise intensity and VO(2) (P < 0.05). Pedalling rate per se did not have any influence on heart rate which, in turn, increased linearly with VO(2). These results may help us to understand why competitive cyclists often pedal at cadences of 90-105 rpm to sustain a high power output during prolonged exercise.     

Practical application of ligand efficiency metrics in lead optimisation

The use of composite metrics that normalise biological potency values in relation to markers of physicochemical properties, such as size or lipophilicity, has gained a significant amount of traction with many medicinal chemists in recent years. However, there is no consensus on best practice in the area and their application has attracted some criticism. Here we present our approach to their application in lead optimisation projects, provide an objective discussion of the principles we consider important and illustrate how our use of lipophilic ligand efficiency enabled the progression of a number of our successful drug discovery projects. We derive, from this and some recent literature highlights, a set of heuristic guidelines for lipophilicity based optimisation that we believe are generally applicable across chemical series and protein targets.     

不同小麦品种的根系生理特性,磷的吸收及利用效率对产量影？…

不同小麦品种的分蘖数、叶片数、干物量与根系总吸收面积及活跃吸收面积呈正相关,在低磷处理的相关性均达到显著水平。此各品种收获得期的干物量及籽粒产量亦与株吸磷量及利用效率呈正相关。通过各因素的比较,鉴定出在低磷条件下可获较高产量的品种。